Cytochrome P-450 Enzyme System

A superfamily of hundreds of closely related HEMEPROTEINS found throughout the phylogenetic spectrum, from animals, plants, fungi, to bacteria. They include numerous complex monooxygenases (MIXED FUNCTION OXYGENASES). In animals, these P-450 enzymes serve two major functions: (1) biosynthesis of steroids, fatty acids, and bile acids; (2) metabolism of endogenous and a wide variety of exogenous substrates, such as toxins and drugs (BIOTRANSFORMATION). They are classified, according to their sequence similarities rather than functions, into CYP gene families (>40% homology) and subfamilies (>59% homology). For example, enzymes from the CYP1, CYP2, and CYP3 gene families are responsible for most drug metabolism.

Also Known As:

Cytochrome P450; Cytochrome P 450; Cytochrome P-450; CYP450 Family; CYP450 Superfamily; Cytochrome P-450 Enzymes; Cytochrome P-450 Families; Cytochrome P-450 Monooxygenase; Cytochrome P-450 Oxygenase; Cytochrome P-450 Superfamily; Cytochrome P450 Superfamily; Cytochrome p450 Families; P-450 Enzymes; P450 Enzymes; Cytochrome P 450 Dependent Monooxygenase; Cytochrome P 450 Enzyme; Cytochrome P 450 Enzyme System; Cytochrome P 450 Enzymes; Cytochrome P 450 Families; Cytochrome P 450 Monooxygenase; Cytochrome P 450 Oxygenase; Cytochrome P 450 Superfamily; Enzyme, Cytochrome P-450; Enzyme, P-450; Enzyme, P450; Enzymes, Cytochrome P-450; Enzymes, P-450; Enzymes, P450; Monooxygenase, Cytochrome P-450; Monooxygenase, Cytochrome P-450-Dependent; P 450 Enzyme; P 450 Enzymes; P-450 Enzyme, Cytochrome; P-450 Enzymes, Cytochrome; Superfamily, CYP450; Superfamily, Cytochrome P-450; Superfamily, Cytochrome P450; Cytochrome P-450 Enzyme; Cytochrome P-450-Dependent Monooxygenase; P-450 Enzyme; P450 Enzyme

Enzymes and Coenzymes: 1
- Enzymes: 152586
  - Oxidoreductases: 13671
    - Oxygenases: 333
      - Mixed Function Oxygenases: 2175
        Cytochrome P-450 Enzyme System: 5365
- Cytochromes: 2196
  - Cytochrome P-450 Enzyme System: 5365
Amino Acids, Peptides, and Proteins: 1
- Proteins: 484843
  - Hemeproteins: 194
    - Cytochromes: 2196
      - Cytochrome P-450 Enzyme System: 5365

mouse Cyp2b9 protein

Bio-Agent Context: Research Results